Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

List of thumbnails

< >
341
341 		342
342
343
343 		344
344
345
345 		346
346
347
347 		348
348
349
349 		350
350
< >
page |< < of 701 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="040/01/419.jpg" pagenum="397"/>
              of which is (as hath often been ſaid) the determinate
                <lb/>
              tion and retardation of the parts of the Earth, from whence
                <lb/>
              the Waters have a determinate period put to their decurſions
                <lb/>
              towards the Eaſt, and return towards the Weſt, in the time of
                <lb/>
              twenty ſour hours. </s>
              <s>The other is that which dependeth on the
                <lb/>
              per gravity of the Water, which being once commoved by the
                <lb/>
              primary cauſe, ſeeketh, in the next place, to reduce it ſelf to
                <emph type="italics"/>
                <lb/>
              quilibrium,
                <emph.end type="italics"/>
              with iterated reciprocations; which are not
                <lb/>
              mined by one ſole and prefixed time; but have as many
                <lb/>
              ties of times as are the different lengths and profundities of the
                <lb/>
              receptacles, and Straights of Seas; and by what dependeth on
                <lb/>
              this ſecond principle, they would ebbe. </s>
              <s>and flow, ſome in one
                <lb/>
              hour, others in two, in four, in ſix, in eight, in ten, &c. </s>
              <s>Now if
                <lb/>
              we begin to put together the firſt cauſe, which hath its ſet Period
                <lb/>
              from twelve hours to twelve hours, with ſome one of the
                <lb/>
              dary, that hath its Period
                <emph type="italics"/>
              verb. </s>
              <s>grat.
                <emph.end type="italics"/>
              from five hours to five
                <lb/>
              hours, it would come to paſſe, that at ſometimes the primary
                <lb/>
              cauſe and ſecondary would accord to make impulſes both one
                <lb/>
              and the ſame way; and in this concurrency, and (as one may call
                <lb/>
              it) unanimous conſpiration the flowings ſhall be great. </s>
              <s>At other
                <lb/>
              times it happening that the primary impulſe doth, in a certain
                <lb/>
              manner, oppoſe that which the ſecondary Period would make,
                <lb/>
              and in this conteſt one of the Principles being taken away, that
                <lb/>
              which the other would give, will weaken the commotion of the
                <lb/>
              Waters, and the Sea will return to a very tranquil State, and
                <lb/>
              almoſt immoveable. </s>
              <s>And at other times, according as the two
                <lb/>
              aforeſaid Principles ſhall neither altogether conteſt, nor
                <lb/>
              ther concur, there ſhall be other kinds of alterations made in
                <lb/>
              the increaſe and diminution of the ebbing and flowing. </s>
              <s>It may
                <lb/>
              likewiſe fall out that two Seas, conſiderably great and which
                <lb/>
              communicate by ſome narrow Channel, may chance to have, by
                <lb/>
              reaſon of the mixtion of the two Principles of motion, one
                <lb/>
              cauſe to flow at the time that the other hath cauſe to move a
                <lb/>
              contrary way; in which caſe in the Channel, whereby they
                <lb/>
              imbogue themſelves into each other, there do extraordinary
                <lb/>
              conturbations inſue, with oppoſite and vortick motions, and
                <lb/>
              moſt dangerous boilings and breakings, as frequent relations
                <lb/>
              and experiences do aſſure us. </s>
              <s>From ſuch like diſcordant
                <lb/>
              ons, dependent not onely on the differenr poſitions and
                <lb/>
              tudes, but very much alſo upon the different profundities of the
                <lb/>
              Seas, which have the ſaid intercourſe there do happen at
                <lb/>
              times different commotions in the Waters, irregular, and that
                <lb/>
              can be reduced to no rules of obſervation, the reaſons of which
                <lb/>
              have much troubled, and alwayes do trouble Mariners, for that
                <lb/>
              they meet with them without ſeeing either impulſe of winds, or </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum